I used the switch statement it made things easy for me

You're really close! It looks like each of your branches has a minor mistake or 2.

1. You want to be using = for assignment, not == which is for comparison.

2. Right now you'll never hit this branch, because you're checking for the tracks property on the whole collection, you want to check it for a specific id.

You're also catching one test you don't want to be in this branch. updateRecords(collection, 2548, "tracks", "") will go to this branch, because it has the property tracks. You also need to check that it doesn't have a value.

Once you're in there, you're really close! You just want to push only the new track (aka value) not an array of the value. push will put whatever you give it into the array, it doesn't squish 2 arrays into 1 (concat does that)

3) You'll see when you're hitting this branches it says TypeError: Cannot read property 'push' of undefined. This makes sense because object[id][prop] which in the first test parses to collection[5439]tracks doesn't exist, and you can't push to an array that doesn't exist. You just want to assign it to your value instead.

4) You're just missing the return statement here :)

Without further ado, this is how I would modify your code to pass all the tests:

function updateRecords(object, id, prop, value) {
  if (prop !== "tracks" && value !== "") {
    object[id][prop] = value;
    return object; 
  } else if (prop == "tracks" && object[id].hasOwnProperty("tracks") && value) {
    object[id][prop].push(value);
    return object;
  } else if (prop == "tracks" && value !== "") {
    object[id][prop] = [value];
    return object;
  } else if (value == "") {
    delete object[id][prop];
    return object
  }
}

Finally here is how I would refactor / reorganize your code to make it a little cleaner. This step is totally optional though!

function updateRecords(object, id, prop, value) {
  if (!value) {
    delete object[id][prop];
  } else if (prop !== "tracks") {
    object[id][prop] = value;
  } else if (object[id].hasOwnProperty("tracks")) {
    object[id][prop].push(value);
  } else {
    object[id][prop] = [value];
  }
  return object
}